Thermally stable conductive polymers for electrochemical gas sensor applications

a technology of electrochemical gas sensor and conductive polymer, which is applied in the direction of instruments, material analysis, measurement devices, etc., can solve the problems of thermal stability, long time to stabilize when subjected to the target gas, and reducing the signal to noise ratio

Active Publication Date: 2022-09-27
ADVENT TECH HLDG INC
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention is about a type of durable aromatic copolymer that can be used in electrochemical gas sensors. These copolymers have nitrogen groups infused in an inorganic acid as electrolytes. The invention also includes membrane electrode assemblies made with these copolymers for use in gas sensors. The technical effect of this invention is to provide materials that can improve the accuracy and reliability of electrochemical gas sensors.

Problems solved by technology

One drawback with a conventional electrochemical sensor is that its size (e.g., volume of electrolyte and size of electrodes) is relative large so that it takes a long time to stabilize when subjected to the target gas.
Further, since the change in current in response to a gas is small, there is a low signal to noise ratio, and there are losses and RF coupling due to metal traces leading to processing circuitry external to the sensor, further reducing the signal to noise ratio.
), porous polyethlyelene, or porous polypropylene do not have the thermal stability to survive direct soldering and thus need additional measures that increase the size and / or power needed to operate.
In fact, the power consumption of these sensors is the lowest of all gas monitoring sensors, and thus the smaller the unit, the lower power is consumed.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Thermally stable conductive polymers for electrochemical gas sensor applications
  • Thermally stable conductive polymers for electrochemical gas sensor applications
  • Thermally stable conductive polymers for electrochemical gas sensor applications

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0022]An acid-imbibed 2 cm2 sample of the thermally stable aromatic backbone polymer of structure 2 is subjected to direct contact with molten solder, such as that commonly available (McMaster-Carr, www.mcmaster.com, part number 766A52). Prior to contact with the molten solder, the membrane sample is weighed. After the molten solder has solidified, it is removed and the membrane is weighted again. Table 1 illustrates three replicates of this process, and the resulting percent change in weight between 1.13% and 3.21% illustrates the thermal stability of this material even upon direct contact with molten solder, considered an extreme condition.

[0023]

TABLE 1Structure 2 membrane weight loss upon contact with molten solderMembraneStructure 2ConditionImbibed with 85% Phosphoric Acid and surface was pat dryUnits usedGramsMeasurementChange innumberBefore solderAfter soldermass% change10.01560.01510.00053.21%20.01510.01490.00021.32%30.07080.070.00081.13%

example 2

[0024]An acid imbibed sample of the polymer of structure 2 is subjected to high temperatures for an extended period of time, whereby the percent weight loss is recorded versus temperature. A thermogravimetric analyser is employed with a platinum cup to hold samples. The temperature ramp rate is set to maximum (>50° C. per minute) up to 200° C. whereby the overshoot in temperature, due to the fast ramp rate, extends to 280° C., the point where typical solder reflow occurs. A sample of pure 85% phosphoric acid is first subjected to this sequence in order to measure the amount of water and phosphoric acid vapor that would be lost. This is illustrated in FIG. 1A, whereby a total of 17.3% liquid weight is lost under this thermal profile. A sample of structure 2 is then imbibed with 85% phosphoric acid is subjected to the same thermal profile. FIG. 1B illustrates the results. In this case, a total of 18.5% weight is lost, a difference of 1.3%. Considering that the thermally stable aromati...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
temperaturesaaaaaaaaaa
conductivityaaaaaaaaaa
temperaturesaaaaaaaaaa
Login to View More

Abstract

Aromatic polymers exhibiting thermal stability and conductivity upon imbibement into an acid are disclosed for electrochemical gas sensor applications. Membrane electrode assemblies for electrochemical gas sensors are also provided, comprising a sensing electrode, a counter electrode, and a polymer membrane comprising the polymers of the present invention, disposed between the sensing electrode and the counter electrode.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit of U.S. Provisional Patent Application No. 62 / 635,582, filed Feb. 28, 2018, which is incorporated by reference herein in its entirety.FIELD OF INVENTION[0002]The present invention relates to an improvement in the assembly of electrochemical gas sensors through incorporating a class of thermally stable conductive aromatic polymers comprising aromatic groups containing one or more nitrogen groups whereby said class of polymers are infused in an inorganic acid.DESCRIPTION OF THE RELATED ART[0003]Electrochemical gas sensors are gas detectors used for measuring the concentration of a target gas by oxidizing or reducing the gas at an electrode and measuring the resulting current. The first electrochemical sensors were developed in 1950s for monitoring oxygen. By the mid-1980s, miniaturized electrochemical sensors came into existence for detecting various toxic gases. Currently, a wide range of electrochemical ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & AuthorityPatents(United States)
IPC IPC(8): C08G65/40G01N27/404C08L81/06C08G75/23
CPCC08G65/4037C08G75/23C08L81/06G01N27/404C08G65/4056
InventorDE CASTRO, EMORY SAYRECHOCHOS, CHRISTOS L.GOURDOUPI, NORAGREGORIOU, VASILIS G.PALOUMBIS, GEORGE
OwnerADVENT TECH HLDG INC